Various medical procedures require that one or more medical fluids be injected into the patient. Medical imaging procedures oftentimes involve the injection of a contrast media into the patient, possibly along with saline or other fluids. Other medical procedures involve injecting one or more fluids into a patient for therapeutic purposes. Power injectors may be used for these types of applications.
A power injector generally includes what is commonly referred to as a powerhead. One or more syringes may be mounted to the powerhead in various manners (e.g., detachably; rear-loading; front-loading; side-loading). Each syringe typically includes what may be characterized as a syringe plunger, piston, or the like. Each such syringe plunger is designed to interface with (e.g., contact and/or temporarily interconnect with) an appropriate syringe driver that is incorporated into the powerhead, such that operation of the syringe driver axially advances the associated syringe plunger inside and relative to a barrel of the syringe. One typical syringe driver is in the form of a ram that is mounted on a threaded lead or drive screw. Rotation of the drive screw in one rotational direction advances the associated ram in one axial direction, while rotation of the drive screw in the opposite rotational direction advances the associated ram in the opposite axial direction.
Contrast media may be injected by a power injector into a patient's heart for an imaging operation, such as for a computed tomography angiogram. In an attempt to have the enhancement levels of the right and left sides of the patient's heart be more uniform, where this enhancement is provided by a contrast media injection, power injectors have been configured to use an injection protocol that in turn utilizes a flow rate decay constant. Such a flow rate decay constant provides an exponentially decaying flow rate injection.